Throttle position sensors on a 1987 Audi 4000 Quattro

[Huw Powell]

Yes, the idle switch is just a matter of getting it to barely activate.

The WOT switch usually seem to "close" at about 2/3 throttle or so 
(which is about sixty degrees of rotation, full close to full open is 
about ninety).

All it does is richen the mixture a bit.

- Huw

On 5/6/2015 1:24 PM, David Vanden wrote:
> I adjusted the existing throttle idle switch and that did not seem hard
> unless I did something wrong.  I guess the trick is getting it in just
> the right place.  The full throttle switch looks more problematic to
> me.  I think I may have finally located a switch assembly. If it is the
> right part, how close to the throttle linkage that activates it do you
> position the top (full throttle sensor).  I mean how much should the
> linkage have to travel before touching/activating the switch?
>
>
>
> On Tue, May 5, 2015 at 7:37 PM, Huw Powell <audi at humanspeakers.com
> <mailto:audi at humanspeakers.com>> wrote:
>
>     The red and black don't matter, since you are just testing a pair of
>     switches.
>
>     The readings should be open (infinite or no reading) or zero.
>
>     The idle switch is under the throttle body and the WOT switch is on
>     the top (so you can trigger it manually).
>
>     I forget which terminal is the "common" one, but it's probably the
>     center one.
>
>     Measuring from the common terminal to idle should be zero with the
>     throttle closed, and open with it cracked even a bit.  With the
>     engine off you might even be able to hear the switch actuate.
>
>     Common to WOT should be open until the lever switch on top of the
>     throttle body is closed by the moving metal bit that actuates it,
>     then it should be closed.
>
>     20 ohms is a dirty switch, or inaccurate meter, or low batteries, or
>     all three.
>
>     The assembly - two switches with wires going to one connector - used
>     to be a dealer part, I paid 62.50 for one back in July 2000.  The
>     idle switch is a bit fidgety to install and adjust.
>
>     - Huw
>
>     On 5/5/2015 5:25 PM, dvanden46 at gmail.com
>     <mailto:dvanden46 at gmail.com> wrote:
>
>         Does anyone know the correct way to check the throttle position
>         sensors on the throttle body of a 1987 Audi 4000 Quattro?  If
>         someone could tell me the specifics I would appreciate it.  I
>         think I did it right using a multi meter but I am unsure.  I set
>         it to ohms and I checked the resistance by placing the red probe
>         on the outside contact of the plug and the black probe on the
>         middle one. This was with the throttle at idle. There was no
>         reading.  Likewise there was no reading when I placed the red
>         probe on the inside contact and the black probe on the middle
>         contact.  I believe they were both supposed to read zero under
>         the circumstances.
>
>
>         With the throttle open and the full throttle switch activated I
>         got a reading in the 20’s or something for the full throttle
>         switch, but I believe it was supposed to be zero.  All this
>         makes me think that the sensors are duds.  But, if someone could
>         confirm how to properly test and what are correct readings I
>         would appreciate it.  Also, if anyone has found micro switches
>         that can be used to replace the faulty ones (assuming they are
>         faulty) so I don’t have to buy another throttle body, please
>         tell me where they can be gotten.
>
>
>         Sincerely,
>
>
>         David Vanden
>
>
>
>
>
>
>         Sent from Windows Mail
>
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